Die cushion



2 ShutsSheot 2 Spt- 30, 1930. s. MARGHITAN DIE CUSHION Filed sept. 22. 192s Patented Sept. 30, 1930 Umano STATES -P maar eFH-ce SAMUEL MARGHITAN, .orCnnCAeo, ILLINos, 4Assrenon Yfro MARQUETTE ToofL sa MFG.

COMPANY, or CHICAGO, -rmiiivorsr A CetaraBarron :or rumors DIE CUsi-rroiv Application led September 22, 1928. `serial-No. 307,873. v

This invention relates to die cushions, and its principal Objectis to provide cushioning means wherein the resistance to 'the pressure, affordedby the descending'die, isnot substantially increased as vthe die proceeds to the lower limit of its working stroke. There are many 'instancesin die 'press worl; Where it is desirable tov maintain a substantially constant Thexinvention consists, therefore, in cush-V ioning means for the dies of die presses, in which is'embodied a spring or other yielding 2o medium for exerting pressure in one direction against the dies, capab-le of bodily movement away from the work without-substantially varyingpthe'eectiveness ofthe spring. It 'further consists in a cushioning means 26 having .mechanism lor holding itin opposition tothe work at a substantially constant pressure, but permitting it tormovebodily away from the work 'without substantially changing its eilective resistance.

lt further consists in the several novel teatures of construction, arrangement and combin ations of parts hereinafter ALfully described and claimed.

` The invention is clearly illustrated inthe accompanying drawings, in whichv Figure 1 .is a view, partly in side elevation and partly in vertical section, of a die press partly broken away, and showing the saine equipped with a die 'cushion embodying a simple `:term of the present invention; y

Fig. 2 is a detail `horizontal section italien on the lin'eQ-Qof 1; u

is adetail vertical section `.through the die cushion, showing the same upon an enlarged scale;A and Fig. 4; is a perspective view'of a certain gear segment which forms ,part of the device. AReferring to `said drawings, which illus? trate one embodiment oitheipresent invention, -the reference character designates 18, as shown at 2Q. The stationary sleeve'Ql the bolster and' '11the `frame of adic press of conventional form. Upon the bolster is secured 'the stationary die 12, and co-operating with said stationary die isthe moving die 13 which is carried by the ram 14 as usual which is reciprocated by power operated actuating mechanism. Standards or posts 10a extend up from 'the bolster and serve 'to fluide the ram in its movements` relative to the lower or stationary die.

AIn the form of die mechanism illustrated, a draw ring 15 is shown, against whichthe work, designated by a, isheld in frictionatl engagement by the upper `die 13 during its down or working stroke. As usual, "the draw'ring is supported on draw .ring pins 16 which extend through and are guided in the bolster. Said draw ring pins move with the draw ringand rest upon 'the die cushion '17 which forms the subject matter oflthis invention, and will now be describedin detail.

ln'the iormoii the invention illustrated, a gear housing 18 is provided which,.as shown, h as atop plate 19 upon which'the draw ring pins '1G stand, andtransmit the pressure ifrom 75 the movingdieto the die cushion. Said gear housing 1S is mounted to move in alignment withthje direction of movement of the upper die, and is 1here shown as provided .with a stem or sleevc'QOon its lower side which is slidably mounted on a fixed, or stationary, slee-ve 21 supportedby the bolster otithe press. Conveniently the stem or sleeve 2O may have threaded connection withithe gear housing issnpportingly connected tothe bolster by a 4tiere d 23 which extends up througlrthe sleeve 21 and is securedin the bolster by a threaded 4connection as at Q4. Gn the'lowerl'end oitthe tie rod is a nut Q5 and washer`26,'the 'latter of which bears against the lower end ofthe stationary sleeveV 21 .and secures '.it against endwise. movement. p

"Between the stationary sleeve 21 and :top plat-'e 19 ofthe gearhousing 18 isa stationary rack bar 27 Awhichfhas racl'teeth 28 ontwo or more of its faces, andbetween the rack bar 27 and bolsterjis a stationary sleeye 29 rwhich abuts Vagainst the lower face ofth'e bolster. The stationary sleeve 21 a-nd'QQvand the rack leo bar QT are tied or secured to the bolster against endwise movement by the tie rod 23, nutand washer 2o. The stationary sleevesI :21. am 2l) and rack bar 27 may be formed in one piece or several as desired.

Connected to the gear housing 1.8 by connectino mechanism, hereinafter described, is a linkl'snpporting collar or bearing member 3() which surrounds the stem or sleeve 2() and is movable lengthwise thereon, and bearing against the lower side of said collar 30 is a coiled compression spring 3l, or other yielding cushioning member, which serves to yieldingly resist the downward movement ott the gear housing and parts directly supported thereby. The coiled con'xpression spring 3l is conlined between the low lr side otl the collar il() and a. nut 52 and interposed washer 33 adjnstably held on the threadial lower end ot the stem 2l). lt isto be. understood that the action ot the eon'ipression spring 3l is transmitted Jfrom ythe lower end of the stem 2t) to the top plate 19 oi the gear housing 18 through the collar 30 and certain connecting members, which will. now be described.

lliieshing with the rack teeth ol the .rack bar 2T are gear segments Bel, the teeth of which are formed on the circumferences oi disks 35 (see F ig. 4) and project laterally trom one of the faces thereof, as is clearly shown in said ligure. Each disk has a hub portion 36 through which extends a journal pin or short shaft 37 which is mounted in side plates or trame members 38 that project down from the top plate 19 or' the gear housing and connect with the stem 2O through the threaded connection at 22. The pins or shafts Si are disposed in a line ruiming at right angles to the axes ot thc sleeve.l and tie rod, and the radii of: the gear segments are of equal length.

The hub portions 36 are in the torni of eccentric blocks, and upon said eccentric blocks are mounted the upper ends 39 ol links 4J), the lower ends ot' which are connected to the collar 30 by pins l1. The upper ends ot the links l() are contained in the space between the side faces of the disks 35 aud inner faces ot the side plates 38 (see Fig. 2). lilith the eccentric blocks 36 located with respect to the gear segments. as shown in the drawings. the major thereof become disposed horizontally when the gear housing has been moved downwards a distance approximately equal to one halt ot its stroke. This location ot the eccentric blocks is not essential to the invention broadly considered as it may be varied as desired.

In the operation of the die cushion, and with the gear housing moved up against the bolster l0, the compression spring 3l presses upward on the collar 30, which transmits the upward pressure to the gear housing 1S through the links 40, eccentric blocks 36 and pins 87. Because of the intermeshing rack bar and gear segments, the major aXcs of the eccentric blocks have been rotated around the axes oi the pins il? from the position seen in full lines in Fig. 2l to one approximating the vertical, or at least approximately forty-live degrees to the horizontal.

if now a sheet of metal is placed between the two dies, and the upper die is brought down upon the work, it will tirst clamp its edge portion upon the draw ring and then move the work down, in drawing it, at the same time forcing down the draw ring 'l5 and therewith the draw ring pins 16, the latter 'forcing down the gear housing 18 a distance corrcspmiding to the distance traveled by the draw ringl pins. rlhe downward pressure on the gear housing is transn'iitted to the pins lli and thence to the ecceiltric blocks 3G and lroin them to the links 40, which in turn transmit the pressure to the. collar il() and thence to the compression sl'n'ing ill, which transmits it to the collar 38 on the stem 2l) ot the gear housing. However, inasmuch as the 'ear segments are bodily moved down with gear housing, they roll down the rack bar and turn the eccentric blocks on the axes oil the gear segments, thereby moving down the links relative to the gear housing and compressing the spring 3l slightly. lVhen the pressure is removed from the top of the gear housing, the spring 3l forces the collar and links upward, thereby turning the gear segments back and, consequently, lifting the gear housing up against the bolster.

claim as new, and desire to secure by Letters Patent:

l. In a die cushion, the combination of a ack bar fixed against endwise movement, a gear housing movable lengthwise of said rack bar, a gear segment meshing with said rack bar and rotatably mounted on said gear housing, an eccentric block eccentrically disposed on said gear segment, a link mounted upon said eccentric block, and resilient means held under compression between said gear housing and link.

2. ln a die cushion, the combination oi a rack bar, lixcd against endwise movement, a` Igear housing movable lengthwise of said rack bar, gear segments meshing with said rack bar and rotatably mounted in said gear housing. eccentric blocks. one disposed on each gear segment, links. one lnounted upon cach eccentric block, and resilient means held under connrnession,between said gear housing and links.

3. ln a die cushion, the combination ol a` rack bar, tixed against endwisc movement, a gear housing movable lengthwise of said rack bar, gear segments meshing with said rack bar and rotatably mounted in said gear housing, eccentric blocks, one eccentrically disposed aroundl the axis of each gear segment, links, one mounted on each eccentric block, a. link supporting collar, and a coiled compression spring held-under compression between said link supporting collar and a member connected tosaid gear housing.

4;. In a die cushion, the combination of a of a die press, a gear housing movable lengthwise ot said rack bar and having a downward ly projecting stem, gear segments meshing with said rack bar and rotatably mounted 'i said gear housing, eccentric blocks, one eccentrically disposed around the airis of each gear segment, links, one mounted on each eccentric block, a link supporting collar surrounding said stem and connected to'said links, and a coiled compression spring held under compression between said link supporting collar and a shoulder on said stem.

5. In a die cushion, the combination of a rack bar arranged to be secured to the bolster of a die press, a gear housing movable lengthwise of said rack bar, gear segments ,meshing with said rack bar and rotatably mounted on said gear housing, eccentric blocks, one disposed eccentrically around the axis oi` each gear segment, links, one mounted on each eccentric block, a link supporting collar connected to said links, and a coiled compression spring held under compression between said link supporting collar and an extension of said gear housing.

6. In a die cushion, the combination of a rack bar, a sleeved member Xtending down therefrom, a tie rod extending through said sleeve and rack bar and supporting the same on a die press bolster, a gear housing movable lengthwise of said rack bar and having a downwardly projecting stem surrounding said sleeve, gear segments meshing with said rack bar and rotatably mounted in said gear housing, eccentric blocks, one eccentrically disposed around the axis of each gear segment, links, one mounted on each eccentric block, `a link supporting collar surrounding said stem and connected to said links, and a coiled compression spring held under compression between said link supporting collar and a shoulder on said stem.

7. In a die cushion, the combination ot a rack bar, a sleeved member extending down therefrom, a tie rod extending through said sleeve and rack bar and supporting the same on a die press bolster, a gear housing movable lengthwise of said rack bar and having a downwardly projecting stern surrounding said sleeve, gear segments meshing with said rack bar and rotatably mounted in said gear housing, eccentric blocks, one eccentrically disposed around the axis of each gear segment, links, one mounted on each eccentric block, a link supporting collar surrounding said stem and connected to said links, a collar adjustably secured on said stem, and a coiled compression spring held under compression between said collars. A

8. In a die cushion, a stationary member,

bar arranged to be secured to the bolster spaced movable members, resilient means interposed between the stationary member and the movable members 'lier yieldingly resisting the movement of the latter, a cam device supported by one of the movable members tor movement therewith and with respect thereto, a. link connection between said cam device and the other of said movable members, teeth on the cam device, and a stationary rack with which the teeth engage whereby the cam will be shifted with respect to its support tor inliuencing the said resilient means through the said links and during the movement oli' thelcain with its support.

9. In a die cushion, a stationary member, spaced movable members, resilient means interposed between the stationary membe and the movable members for yieldingly resisting the movement of the latter, an eccentric-ally mounted cam device supported by one ot theV movable members for movement therewith and with respect thereto, a link connection between said cam device and the other of the said movable members, and means tor rotating the cam device with respect to its support during the movement of the cam with its support, for influencing the said resilient means through the said links.

SAMUEL MARGHITAN. 

